During a chemical reaction, two or more chemicals interact and react with each other to form entirely new compounds. What happens to the individual atoms as they go from their original molecule to an entirely different product all together? Think about this for a moment and look at the equation below:
SnO2(s) + 2 H2(g) → Sn(s) + 2 H2O(g)
Tin oxide (SnO2) is reacting with two hydrogen compounds (H2) to form Tin (Sn) and two water molecules. The numbers to the left of the molecules are called the coefficients; they represent how many molecules are present. The numbers to the right of each atom, indicate how many atoms are in the molecule. If there are no coefficients or numbers to the right of each atom, you can assume there is only one. How many molecules of tin reacted with the hydrogen; how much tin did you start out with? Is that the same as the amount of tin that you might find on the product side of this equation, the end result? Balancing equations is important in chemistry, because it gives the chemist an idea of how much reactant is needed to make a desired amount of product. It also allows us to predict with some accuracy the end result of many chemical reactions. We know that formulas need to be balanced because matter doesn't just disappear or come out of thin air after a chemical reaction, but rather it transforms from one form to another. According to the law of conservation of matter, in a chemical reaction, matter cannot be created or destroyed, but can change from one form to another.
In this lab you will model the chemical reaction between Methane (CH4) and Oxygen (O2) to form carbon dioxide and water. The blank lines in front of each element below represents the coefficients. It is your objective in this lab to determine how much methane is needed to react with oxygen in order to form carbon dioxide and water without having any left over atoms or bonds.
_ CH4(g) + _O2(g) → _ CO2(g) + ___H2O(l)
Prelab
1.) What do the numbers to the left of each molecule represent?
2.) What do the numbers to the right of each atom represent?
3.) What does the law of conservation state?
4.) What two molecules react together to form carbon dioxide and water?
5.) Predict: How many molecules of water will be formed from one molecule of methane?
Procedure
1.) Take one methane and one oxygen molecule from you teacher.
2.) Record how many atoms of each element you have.
3.) Try to take apart these two molecules and see if you can form water and carbon dioxide with them, using all of the atoms and bonds.
4.) If you have extra atoms and bonds, you must go up and grab another methane or oxygen molecule, to form more water or carbon dioxide.
5.) Record how many atoms of each element you use.
6.) Repeat until all of the reactants has be turned into product and there are no remaining bonds or atoms left.
Data
Side of Reaction
Carbon atoms used
Hydrogen Atoms used
Oxygen Atoms used
Reactants
Products
Analysis
1.) Does the amount of atoms you have of each element match in the product and reactant side?
2.) How many molecules of methane did you use?
3.) How many molecules of carbon dioxide did you end up with?
4.) Write a balanced equation of the reaction between methane and oxygen?
5.) Why is this equation important, when it comes to the environment? (Hint: Think of why too much carbon dioxide could be bad for our atmosphere)
Conclusion
Was your hypothesis correct?
What was one thing you learned from this lab?
What is one question that you have?
Keeping Track of Atoms
An Introduction into Balancing Equations
During a chemical reaction, two or more chemicals interact and react with each other to form entirely new compounds. What happens to the individual atoms as they go from their original molecule to an entirely different product all together? Think about this for a moment and look at the equation below:
SnO2(s) + 2 H2(g) → Sn(s) + 2 H2O(g)
Tin oxide (SnO2) is reacting with two hydrogen compounds (H2) to form Tin (Sn) and two water molecules. The numbers to the left of the molecules are called the coefficients; they represent how many molecules are present. The numbers to the right of each atom, indicate how many atoms are in the molecule. If there are no coefficients or numbers to the right of each atom, you can assume there is only one. How many molecules of tin reacted with the hydrogen; how much tin did you start out with? Is that the same as the amount of tin that you might find on the product side of this equation, the end result? Balancing equations is important in chemistry, because it gives the chemist an idea of how much reactant is needed to make a desired amount of product. It also allows us to predict with some accuracy the end result of many chemical reactions. We know that formulas need to be balanced because matter doesn't just disappear or come out of thin air after a chemical reaction, but rather it transforms from one form to another. According to the law of conservation of matter, in a chemical reaction, matter cannot be created or destroyed, but can change from one form to another.
In this lab you will model the chemical reaction between Methane (CH4) and Oxygen (O2) to form carbon dioxide and water. The blank lines in front of each element below represents the coefficients. It is your objective in this lab to determine how much methane is needed to react with oxygen in order to form carbon dioxide and water without having any left over atoms or bonds.
_ CH4(g) + _O2(g) → _ CO2(g) + ___H2O(l)
Prelab
1.) What do the numbers to the left of each molecule represent?
2.) What do the numbers to the right of each atom represent?
3.) What does the law of conservation state?
4.) What two molecules react together to form carbon dioxide and water?
5.) Predict: How many molecules of water will be formed from one molecule of methane?
Procedure
1.) Take one methane and one oxygen molecule from you teacher.
2.) Record how many atoms of each element you have.
3.) Try to take apart these two molecules and see if you can form water and carbon dioxide with them, using all of the atoms and bonds.
4.) If you have extra atoms and bonds, you must go up and grab another methane or oxygen molecule, to form more water or carbon dioxide.
5.) Record how many atoms of each element you use.
6.) Repeat until all of the reactants has be turned into product and there are no remaining bonds or atoms left.
Data
Analysis
1.) Does the amount of atoms you have of each element match in the product and reactant side?
2.) How many molecules of methane did you use?
3.) How many molecules of carbon dioxide did you end up with?
4.) Write a balanced equation of the reaction between methane and oxygen?
5.) Why is this equation important, when it comes to the environment? (Hint: Think of why too much carbon dioxide could be bad for our atmosphere)
Conclusion
Was your hypothesis correct?
What was one thing you learned from this lab?
What is one question that you have?